# Mathematics Colloquia and Seminars

Return to Colloquia & Seminar listing

### Hund's rule and metallic ferromagnetism

**Mathematical Physics & Probability**

Speaker: | Daniel Ueltschi, University of Arizona |

Location: | 693 Kerr |

Start time: | Tue, May 17 2005, 3:10PM |

The origin of ferromagnetism in metals is an old question that has not received a complete answer to this day. We investigate a model of itinerant electrons in two different bands, interacting via Coulomb repulsion and Hund's rule. In the case of anisotropic on-site exchange interactions, we prove that ground states have macroscopic magnetization, and that there is no energy gap. This is a joint work with J. Froehlich.